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A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Boxes represent hazard ratios, and vertical lines are 95% confidence intervals. Box size is inversely proportional to the width of the confidence interval. ER, oestrogen receptor; NK cells, natural killer cells.
